1. Field of the Invention
The present invention relates to illumination devices and, in particular, to an adjustable lamp shade or shield formed from at least two laterally spaced arrays of light deflectors.
2. Description of the Related Art
Most lighting fixtures whether floor lamps, wall mounted light fixtures or ceiling fixtures, have diffusers or shades to prevent the light emitted from the light source from shining in the user's eyes, to direct the light towards the object or area to be lit, and/or for aesthetic purposes For example, floor and table lights typically have a shade which is semi-cylindrical or is conical to direct the light from the light source downwardly onto the surface of the desk or table, or towards a reading chair or the like.
A significant deficiency of conventional lamp shades and deflectors is that the intensity of light directed in a particular direction can not be altered, unless the entire shade is moved. For example, the light emitted from desk lamps is directed almost entirely downwardly. Accordingly, additional lamps and/or ceiling lights are typically required to fully illuminate a room. Likewise many wall mounted lamps have shades which direct substantially all of the light against or along the wall whereby the surrounding area will be only dimly lit. Thus, ceiling lights or a great number of fixtures must be provided for total lighting.
Further, because light emanating from a light source is typically confined to a particular area by lamp shades, a high light intensity is required if there is to be any peripheral lighting. Thus, a relatively high wattage light source is required for shaded lamps to achieve a given level of peripheral lighting.
Efforts have been made heretofore to produce devices for controlling the amount and direction of light emitted from a light source. For example, 3-way light bulbs and dimmer switches are commonly used to offer the user a variety of light intensities. Such devices, however, do not allow directional intensity variation.
Others have developed shades which allow the user to vary the amount of light allowed to pass therethrough. Typically, such shades are in the form of a plurality of louvers disposed either in a single plane in front of a spot or track light or in a cylinder surrounding the light source.
For example, U.S. Pat. No. 4,800,473 to Tremblay shows a lamp having a series of louvers that are lengthwise pivotable between an opened and a closed position. The louvers are simultaneously adjusted through the use of an annular gear mounted on the lamp base.
U.S. Pat. No. 2,437,825 to Kohn shows a lamp shade with a plurality of pivoting blades. The movement of a control ring causes rotation of the blades from an opened position to a closed position. Again, the blades are interconnected so that all blades are adjusted simultaneously.
U.S. Pat. No. 188,700 to Von Otter and U.S. Pat. No. 2,670,431 to Bullock also relate to lamp shades that have adjustable louvers that are simultaneously adjusted.
A problem common to each of the above-identified lamps is that the louvers cannot be independently adjusted to allow a higher degree of flexibility in directing the illuminating light.
Because the light deflectors of the above-noted structures can only be altered in unison, the resulting lighting effect is typically an all or nothing effect. The light is either allowed to pass through the shade or it is not and the user does not have the opportunity to adjust lighting in accordance with the particular environment in which the light fixture is used. Even if intensity passing through the shade can be gradually increased or decreased, only limited directional control is possible and, therefore, the light emitted can not be effectively utilized to maximize energy efficiency.
My earlier U.S. patent application No. 07/789,955, filed on Nov. 12, 1991, the disclosure of which incorporated herein by this reference, addressed these problems by providing a lamp shade wherein at least some of the light deflectors can be rotated independently of one another relative to the support frame. That is not to say, however, that improvement on my original concept is not possible, and, indeed, the invention disclosed herein constitutes an improvement thereof. More particularly, I found that with the light deflectors arranged in a single smoothly contoured array, light may pass through the inevitable crack between adjacent light deflectors thereby precluding a total blackout of light emanating through the lamp shade.
To address that potential concern, one may overlap the light deflectors of a single array. However, with the light deflectors arranged in this manner, it is no longer possible to completely independently rotate each light deflector with respect to the remaining light deflectors.